Adjustable drill pipe stabilizer tool



Dec. 8, 1970 J. E. HAMILToN ADJUSTABLE DRILL PIPE STABILIZER TOOL 3 Sheets-Sheet l Filed May 1, 1968 JAMES E. HAM/TON /Nl/E/VTOR ATTORNEVS Dec. 8, 1970 J. E. HAMILTON 3,545,825

ADJUSTABLE DRILL PIPE STABILIZER TOOL Fv'iled May l, 1968 l 3 Sheets-Sheet 2 JAMES E. HAM/TON I/E N 7' OR.

32 i F/ G. 4 By Heade O/lauel Wlfkou Mamw ATTORNEYS Dec. 8, 19.70 JQ E. HAMILTON 3,545,825

ADJUSTABLE DRILL PIPE STBILIZER TOOL Filed May l, 1968 42 5 Sheets-Sheet 5 FIG.l 6 25 3o '/40 JAMES E. HAM/TON /Nl/E/VTOR,

BV Hayden pmu/ef lis/14m MallLeM/ United States Patent O 3,545,825 ADJUSTABLE DRILL PIPE STABILIZER TOOL James E. Hamilton, Rte. 1, Box 97B, Holden, La. 70744 Filed May 1, 1968, Ser. No. 725,620 Int. Cl. F16c .79/10 U.S. Cl. 308--6 1 Claim ABSTRACT OF THE DISCLOSURE A drill pipe stabilizer tool for stabilizing the position of a drill string relative to the wall of a well bore during the drilling of the well bore. The tool includes a plurality of circumferentially spaced bearing members which eX- tend laterally from the drill string and which are adapted to bear against the wall of the well bore when the portion of the drill string in the vicinity of such members moves too close to the wall of the well bore. The tool includes means for adjusting the lateral distance by which the bearing members extend out from the drill string.

BACKGROUND OF THE INVENTION This invention relates to drill pipe stabilizer tools for stabilizing the position of a drill string relative to the wall of an oil well type of well bore during the drilling of the-well bore.

Drill pipe stabilizer tools which have been heretofore proposed have included a tubular body member in the form of a short section of drill pipe which is connected into the drill string and a number of blade members fixed to the tubular body member to form extensions therefrom. During drilling, these blade members serve to contact the wall of the well bore and, thus, to hold the drill string away from the wall of the well bore. Depending on the particular requirements, the overall diameter of the stabilizer tool including the blade members may be somewhat less than the nominal diameter of the well bore, in which case the blade members only contact the well bore wall when the drill string drifts too far olf the center line of the well bore.

Such drill pipe stabilizer tools serve various useful purposes. They reduce friction of the drill pipe on the wall of the well bore and reduce the possibility of sticking the drill pipe. They also reduce wobbling and whipping of the drill string during the rotation thereof as the hole is being drilled. Also, if a stabilizer tool is placed in the drill string just above the drill bit attached to the bottom of the drill string, then the `rigidity produced by the stabilizer tool limits the lateral freedom of movement of the drill bit and enables the `Well bore to be drilled on a straighter course.

Stabilizer tools are also sometimes used in directional drilling to cause deliberate deviation of the course of the well bore from a straight line path. In this case, a stabilizer tool is placed in the drill string just above the drill bit and used as a fulcrum point. Weight is applied to the drill bit and the lever action about the fulcrum point causes the drill string to be bowed and thus changes the direction of the drill bit. As a result, the well bore is deliected at an angle from the Vertical as the drilling continues. By using stabilizer tools of varying overall diameters spaced at varying distances above the drill bit, the lever action can be modiiied to suit the need of deflection by either enhancing the leverage to create more deection or reducing the leverage to create less deflection.

In the drill pipe stabilizer tools heretofore proposed, the blade members are rigidly xed to the drill pipe body member and the distance by which the blades extend from the body member cannot be changed except by cutting off part of the blade members or by welding additional material to the outer edges of the blade members. In the course of drilling a well bore, however, various different sizes of stabilizer tools are required, that is, stabilizer tools having various different overall diameters are required. Thus, it has been heretofore necessary to provide a stock of stabilizer tools of varying sizes at the well site. As an example, for the case of a 9 and 7A; inch diameter well bore, there is need for stabilizer tools ranging in size from 9 inches to 9 and 'Ms inches and, in many cases, it is desired that such sizes be graduated by a factor of of an inch. This would require the availability of stabilizer tools of fifteen different sizes or overall diameters.

Another problem with stabilizer tools is the wearing down of the wall contacting surface of the blade members. Since minute changes of diameter on the order of 1A; of an inch affects the control of the well bore path, the stabilizer tools must be changed when such wear occurs. Because of much abrasion in well boring, this wear can occur within a few hours time. For this reason, the wall contacting surfaces of the blade members of stabilizer tools heretofore used have usually been coated with a 1/16 inch coating of hard metal to give the blade members a longer Wearing life. Eventually, however, this coating is worn off and the stabilizer tool is no longer in gauge. It must be changed and a new one put in its place. In addition to the time and expense involved in changing stabilizers, this also means that a greater number of stabilizers must be provided at the well site.

SUMMARY OF THE INVENTION It is an object of the invention, therefore, to provide a new and improved method of adjusting the size of a drill pipe stabilizer tool.

It is another object of the invention to provide a new and improved drill pipe stabilizer tool which is adjustable to provide a wide range of stabilizer. sizes.

It is a further object of the invention to provide a new and improved drill pipe stabilizer tool which can be used for a much longer period of time before the wall contacting elements thereof have to be replaced.

In accordance with one feature of the invention, there is provided a drill pipe stabilizer tool for stabilizing the position of a drill string relative to the wall of a well bore during the drilling of the well bore. Such tool includes a tubular body member adapted to be connected in the drill string. The tool also includes a plurality of elongated bearing members which are adapted to bear against the wall of the well bore when the portion of the drill string in the vicinity of the body member moves too close to the wall of the well bore. The tool further includes means for attaching the bearing members to the exterior of the tubular body member with the longitudinal axes of the bearing members running parallel to the longitudinal axis of the body member and `with the bearing members spaced apart around the circumference of the body member. The tool also includes means for adjusting the lateral distance by which the bearing members extend out from the body member.

In one embodiment of the invention, the wall-contacting bearing members take the form of rectangular blocks of metal material which are adapted to be slipped into corresponding longitudinal slots on the tubular body member and the adjusting means include shim members which are adapted to be inserted between the rectangular blocks and the tubular body member for increasing the lateral distance by which the rectangular blocks extend out from the body member, In another embodiment of the invention, the bearing members take the form of elongated roller members which are mounted in frame members which are adapted to be slipped into corresponding longitudinal slots on the tubular body member and the adjusting means include shim members which are adapted to be inserted between the frame members and the tubular body member for increasing the lateral distance by which the roller members extend out from the body member.

For a better understanding of the present invention, together with other and further objects and features thereof, reference is had to the following description taken in connection with the accompanying drawings, the scope of the invention being pointed out in the appended claim.

BRIEF DESCRIPTION OF THE DRAWINGS Referring to the drawings:

FIG. 1 is an elevational view of one embodiment of a drill pipe stabilizer tool constructed in accordance with the present invention;

FIG. 2 is a cross sectional view taken along the section line 2 2 of FIG. 1;

FIG. 3 is part of a cross sectional view taken along the section line 3 3 of FIG. 1;

FIG. 4 is part of a cross sectional view taken along the section line 4 4 of FIG. 1;

FIG. 5 is an elevational view of another embodiment of a drill pipe stabilizer tool constructed in accordance with the present invention;

FIG. 6 is a cross sectional view taken along the section line 6 6 of FIG. 5;

FIG. 7 is part of a cross sectional view taken along the section 7 7 of FIG. 5; and

FIG. 8 is part of a cross sectional view taken along the section line 8 8 of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1-4, there is shown a drill pipe stabilizer tool 10 which includes a tubular body member 11 having external threads 12 at one end and internal threads 13 at the other end thereof. Threads 12 and 13 enable the body member 11 to be connected into a string of drill pipe at a desired position in such drill string. The body member 11 is made of metal, such as steel, and its overall longitudinal length is ve feet or more. The outside diameter of the cylindrical portion of the body member 11 is typically the same as that of the remainder of the drill pipe in the drill string, for example, eight inches. The body member 11 is provided with an internal passageway 14 (FIG. 2) which runs the entire length of the tool. The body member 11 also includes a plurality of longitudinal slots 15 formed or cut into the exterior portion thereof (as seen in FIGS. 2-4). As indicated in FIG. 2, there are four of these slots and they are evenly spaced at 90 intervals around the circumference of the body member 11.

The body member 11 also includes four built-up members 16 which are also spaced apart around the circumference thereof at 90 intervals. These built-up members 16 are welded to the body member 11, as indicated by the welding beads 17. Each built-up member 16 includes a central opening 18 having the same length and width as the slots 15. The openings 18 are positioned above and in alignment with the slots 15. By way of example, the slots 15 and opening 18 may have a length of 14 inches and a width of two inches, the overall depth from the top of the opening 18 to the bottom of the slots 15 being 2% inches.

The stabilizer tool 10 also includes a plurality of elongated bearing members which, in the present embodiment, take the form of elongated rectangular blocks 20 cornposed of a metal material such as steel. These bearing blocks 20 are sized so that they can be slipped through the built-up openings 18 and into the slots 15 in the body member proper. The height of each block 20 is such that block 20 will, under minimum conditions, protrude or extend a slight distance above the top surface of the built-up member 16. For an overall opening and slot depth of 2% inches, the height of each block 20 would be, for example, 21/2 inches, thus giving a minimum protrusion of 1/8 inch. Each bearing block 20 has inlaid in the outer surface thereof a pair of inserts 21 and 22 composed of pure tungsten. Such inserts may have a thickness of, for example, 1A inch. Such inserts serve to substantially increase the wear life of the bearing blocks 20.

As best seen in FIG. 3, non-circular or oval slots 23 and 24 are cut through each of the bearing blocks 20, one near each end of each block 20 in a plane lateral to the longitudinal axis of each block. These slots 23 and 24 run from one side to the other of each block 20. The bearing blocks 20 are attached to the body member 11 by means of cylindrical retaining pins 25 and 26 which pass through the non-circular slots 23 and 24 respectively. As seen in FIG. 2, the retaining pin 2S is longer than the Width of the bearing block 20 and is held in a retaining pin passageway 27 which is drilled into the body member 11 and the built-up member 16 as indicated and the diameter of pins 25, 26 is less than the longitudinal extent of the oral slots 23, 24. A smaller diameter drive pin passageway 28 is provided at one end of the retaining pin passageway 27 for facilitating the removal of the retaining pin 25. The other end of the retaining pin passageway 27 is internally threaded as indicated at 29 and an Allen head screw 30 is screwed into the threaded portion 29 to hold the retaining pin 25 in place.

The retaining pin 26 at the other end of the bearing block 20 is held in place in the same manner as for pin 25. The Allen head screw for the retaining pin 26 is indicated at 31 in FIG. 1.

The drill pipe stabilizer tool 10` further includes means for adjusting the lateral distance by which the bearing blocks 20 protrude or extend out from the tubular body member #11. This adjusting means includes sets of one or more shim members which are adapted to be placed in the bottoms of the slots 15 so as to lie between the bearing,blocks 20 and the body member 11. In FIG. 2, there is shown in each of the four slots 15 a pair of shim members 32 and 33. The adjusting `means also includes a plurality of jam screws 34 each of which is threaded into an intemally-threaded passageway 35 which communicates with one of the slots 15, this being best seen in FIG. 4. These passageways 35 are drilled at an angle through the built-up member 16 and the body member 11, such angle being in a downward direction relative to the bottom of the slot 15. The jam screws 34 are adapted to be screwed into the passageways 35 and against the sides of the bearing blocks 20 to push the bearing blocks firmly against the shim members 32 and 33. This serves to hold the bearing blocks 20, as well as the shims 32 and 33, securely in place. As indicated in FIG. 1, four of these jam screws 34 are used for each of the bearing blocks 20, two contacting one side of each bearing block 20 and the other two contacting the other side of each bearing block 20'.

In order to adjust the lateral extension of the bearing blocks 20, the Allen head screws 30 and 311 and the retaining pins 25 and 26 are removed. The various jam screws 34 are also loosened so as to discontinue their contact with the blocks 20. The bearing blocks 20 are then removed from their various slots. The appropriate shim members for the desired extension distance are then placed in the bottom of each of the slots 15. The bearing blocks 20 are then replaced in the slots 15. The retaining pins 25 and 26 and Allen head screws 30 and 31 are replaced and, while firmly pushing a bearing block 20 inwardly against the shims, the jam screws 34 are screwed into firm engagement with the bearing block 20. This latter process is repeated for each of the other bearing blocks 20. The sizes and numbers of shims used with each of the different bearing blocks 20 are such that the same total thickness of shim material is used with each of the four bearing blocks 20.

A fairly wide range of lateral extension adjustments is provided by providing a number of different shim members of different thicknesses. For example, four` sets of shims with the shims ranging in thickness from M6 of an inch up to of an inch in 1/16 inch steps can be provided (a total of 6 shims per set). By placing these shims in the bearing block slots in pairs, the total size range is further increased up to of an inch in 1m; inch steps (provided a second 3A; inch shim is provided for th-e maximum 1% inch thickness). Thus, twelve different extension adjustments (thirteen, if the case where no shims are used is counted) are provided.

Among other things, the adjustments provided by the use of the shim members increases the wear lifeof the bearing blocks 20. This is because the lateral extension of the bearing blocks can be increased by adding thicker shims as the wearing surfaces of such bearing blocks 20 wear down. Assuming, for example, that the tungsten inserts 21 and 22 are provided with a 1A inch thickness and that a 1A; inch change in the overall diameter of the stabilizer tool will affect the well bore drilling operation, then the adjustment feature of the present invention increases the wear life of the bearing blocks 20 by a factor of four (remembering that a 1/s inch change in overall diameter corresponds to a 1,46 inch change in the lateral extension of a given bearing block 20). In other words, as the Wearing surfaces of the bearing blocks 20 continues to wear down, the shim members are periodically changed so as to increase the shim thickness in M6 inch increments. In this manner, the drilling operator can enjoy Wear of the entire 1A inch thickness of the tungsten inserts before he has to replace the bearing blocks. In addition to this, the use of solid-tungsten for the inserts serves to provide a further increase in the wear life of the bearing blocks 20.

-Referring now to FIGS. 5-8 of the drawings, there is shown a drill pipe stabilizer tool having a plurality of elongated bearing members 442 which are constructed in a different manner than those of the earlier embodiment. Except for this, the modified embodiment of FIGS. 5-8 is the same as the earlier embodiment. Accordingly, the same reference numerals are used for the parts which are the same.

The details of the modified bearing members 42 are best shown in FIGS. 6-8. As seen in FIG. 7, each bearing member 42 includes an elongated roller member 43 and a frame member 44. The frame member 44 is a generally rectangular block of metal material having a cutout center portion 45 which is adapted to receive the roller member 43. The outside dimensions of the frame member 44 are such that it can be slipped into the slot 15 in the same manner as was the bearing block of the earlier embodi ment. The roller member 43 is held in place by means of a roller pin 46 which rests in recesses or notches 47 and 48 which are cut into the frame member 44, the recess 48 being best seen in FIG. 8. The roller pin 46 is held in the notches 47 and 48 by means of keeper members 49 and keeper screws 50, the latter being threaded into the bottoms of the recesses 47 and 48. The outside diameter of the roller pin 46 is slightly smaller than the inside diameter of the roller member 43 so that the roller member 43 is free to rotate around the axis of the roller pin 46. In this regard, the depth of the recesses 47 and 48 is such that the roller member 43 is held clear of the bottom of the cut-out portion 45 of the frame member 44.

Non-circular or oval slots 51 and 52 are cut through the frame member 44 near the two ends thereof, as best seen in FIG. 7. These non-circular slots 51 and 52 cooperate with the retaining pins 25 and 26 respectlvely, for purposes of attaching the frame member to the tubular body member 11. The other three bearing members -42 of the present embodiment are constructed 1n the same manner as the bearing member 42 shown in FIGS. ,7 and i8. As indicated in FIG. 5, the jam screws 34 are employed to hold the frame members 44 in place.

In use, the fact that the roller members 43 are free to rotate, means that the wear is distributed over the entire circumference of such roller members. This serves to further extend the Wear life of the stabilizer tool elements. As with the earlier embodiment, the lateral or outward extension of the roller members 43 with respect to the body member 11 is increased or decreased by the use of shim members of various sizes and numbers. These shim members, two of which are represented at 32 and 33 in FIGS. 6-8, are placed in the slots 15 so as to lie between the bottom of the frame members 44 and the body of the tubular body member 11.

From the foregoing description of the preferred embodiments of the invention, it is seen that a drill pipe stabilizer tool constructed in accordance with the invention enables drill string stabilization to be provided in an efficient and economical manner and in a manner which provides a large degree of fiexibility and a large degree of choice in the stabilization program. The present invention also provides a stabilizer tool having a greater wear life. The present invention can reduce the previous normal cost of stabilization by as much as 50% in the cost of the tools alone. Further savings are realized in the cost of transportation, handling, storage, maintanance, repair and so forth of such tools. In addition, the present invention makes it much more certain that the drilling operator will have available the correct tool size needed for almost any occasion.

What is claimed is:

1. A drill pipe stabilizer tool for stabilizing the position of a drill string relative to the wall of a well bore during the drilling of the well bore, such too comprising:

a tubular body member adapted to be connected in a drill string;

circumferentially spaced, elongated rectangular blocks on said tubular body member, said blocks each including a bearing surface carried thereon which is adapted to bear against the wall of a well bore for keeping the drill string properly positioned in the well bore;

means for attaching said rectangular blocks to said tubular body member, said means including:

longitudinally extending, circumferentially spaced slots in said tubular body member with each slot having one of said blocks therein;

a non-circular slot adjacent each end of each of said blocks with each of said slots extending from one side to the other of each block and in a plane lateral to the longitudinal axis of each block;

passageway means formed in said tubular body member and aligned with said non-circular slots;

pin means extending through each of said passageway means and through each of said noncircular slots and across said longitudinal slots to attach said blocks in said slots on said tubular body member;

means for adjusting the lateral distance by which each of said blocks extends out from said tubular body member, said adjusting means including:

at least one shim member which is adapted to be placed in the bottom of each of said slots between each of said blocks and said tubular body member for determining the lateral distance by which each of said blocks is extended; and

means for holding each of said blocks in any adjusted position in its respective slot laterally relative to said tubular body member, said holding means including: jam screws extended at an angle in said tubular body member downward toward the bottom of and on each side of each of said slots in said tubular body member for engaging each side of each of said blocks to hold each of said blocks in position in its respective slot relative to said tubular body member.

References Cited UNITED STATES PATENTS King 30S-4X Snyder 30S-244K Prentice 30S- 4X Neuhaus 308-4 Gehrke 175-325X Ortloff et al. 308-4 Garrett 308-4 Raymond 175-346X 8 Grant 175-347X Crickmer l175-346 Reed 308-6A Taylor 175-347 Smith 175-346 Koppl 175--346 Harris 175-346 Emanuel 175-346 Kennedy 30S-4A lo FRED C. MATT-BRN, JR., Primary Examiner F. SUSKO, Assistant Examiner 

